Method of synthesizing higher-molecular alcohol

ABSTRACT

The present invention provides a production method with which high molecular alcohols having an even number of carbon atoms such as 1-butanol, hexanol, octanol and decanol, and a mixture of these are efficiently collected through clean processes with the use of ethanol as a raw material. High molecular alcohols are produced from ethanol by using calcium phosphate-based compounds such as hydroxyapatite Ca10(PO4)6(OH)2, tricalcium phosphate Ca3(PO4)2, calcium monohydrogen phosphate CaHPO4.(0˜2)H2O, calcium diphosphate Ca2P2O7, octacalcium phosphate Ca8H2(PO4)6.5H2O, tetracalcium phosphate Ca4(PO4)2O or amorphous calcium phosphate Ca3(PO4)2. nH2O as a catalyst, using ethanol as a starting material, and setting a contact time at 0.4 second or longer.

INCORPORATION BY REFERENCE

This application is a continuation-in-part application of internationalpatent application Serial No. PCT/JP2005/022217 filed Dec. 2, 2005,which claims priority to Japanese patent application Serial No. JP2004-351307 filed Dec. 3, 2004.

The foregoing applications, and all documents cited therein or duringtheir prosecution (“appln cited documents”) and all documents cited orreferenced in the appln cited documents, and all documents cited orreferenced herein (“herein cited documents”), and all documents cited orreferenced in herein cited documents, together with any manufacturer'sinstructions, descriptions, product specifications, and product sheetsfor any products mentioned herein or in any document incorporated byreference herein, are hereby incorporated herein by reference, and maybe employed in the practice of the invention.

FIELD OF THE INVENTION

The present invention relates to a method for producing high molecularalcohols from ethanol with the use of calcium phosphate-based catalysts.

BACKGROUND OF THE INVENTION

High molecular alcohols such as butanol (C₄H₉OH), hexanol (C₆H₁₃OH),octanol (C₈H₁₇OH), and decanol (C₁₀H₂₁OH) are currently synthesized bythe oxo method using propylene obtained from petroleum as a rawmaterial. However, as crude oil prices exceeded 50 dollars/barrel in2004, and the soaring prices of propylene as a raw material led to therising production cost of high molecular alcohols, the result is aworsened profitability.

The oxo method necessitates the use of deadly carbon monoxide as a rawmaterial in addition to propylene, and the method comprises acomplicated, high-pressure reaction which contributes to the risingproduction costs. Furthermore, the oxo method is unpreferable in view ofenvironmental conservation. As an example, butanol synthesis reactionsinvolve the generation of 2 moles of carbon dioxide as a side productper 1 mole of butanol as shown in reaction (1), and carbon dioxide is awell-known global warming substance.CH₃CH═CH₂ (propylene)+3CO (carbon monoxide)+2H₂O (water)→C₄H₉OH(butanol)+2CO₂ (carbon dioxide)  (1)

Relating to methods for synthesizing 1-butanol from ethanol, both MgOcatalysts (“Dimerisation of ethanol to butanol over solid-basecatalysts” A. S. Ndou, N. plint, N. J. Coville, Applied catalysis A:General, 251, p. 337-345 (2003)) and zeolite (ZSM-5) catalysts on whichalkali metals are supported (“Bimolecular Condensation of Ethanol to1-Butanol Catalyzed by Alkali Cation Zeolites” C. Yang, Z. Meng, J. ofCatalysis, 142, p. 37-44 (1993)) have been used. However, they are notindustrially suitable because of their low selectivity.

International Publication No. WO 99/38822 relates to a method forsynthesizing 1-butanol with the use of calcium phosphate-basedcatalysts, although this synthesis method features disadvantages whichare associated with the high reaction temperature (as high as 350 to450° C.) that is involved. For instance, the selectivity of 1-butanol islow; the catalyst regeneration treatment has to be repeated frequentlybecause of the rapid degradation of catalytic property; the durabilityof devices is decreased; and the fuel cost required for maintaining thereaction temperature is increased.

Thus, there is a clear need for an efficient and clean method ofproducing high-molecular alcohols from ethanol.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a production methodwith which high molecular alcohols having an even number of carbon atomssuch as 1-butanol, hexanol, octanol, and decanol, and a mixture ofthese, are efficiently collected through clean processes, with the useof ethanol as a raw material.

Ethanol, which is the starting material of the process of the presentapplication, is currently synthesized through the conversion of sugarsobtained from sugarcanes, beets, etc., by a fermentation method.Recently, a technique for synthesizing ethanol from biomass,agricultural and forestry residues, has been established, and a strikingincrease in the production of ethanol can be expected in the future. Asa result, the production cost of ethanol is expected to lower to thelevel comparable to that of crude oil. In fact, it is said that theproduction cost of ethanol is about 10 yen/l in Brazil, an advancedcountry in terms of ethanol, and this is comparable to or less expensivethan the international crude oil prices. Therefore, it is consideredthat the process of the present application can obtain high molecularalcohols which are less expensive than those obtained through the oxomethod.

In the method for synthesizing high molecular alcohols according to thepresent application, the raw material may be only ethanol, and thereaction may proceed easily at normal pressure. Further, the sideproduct of the synthesis reaction of high molecular alcohols may be onlywater (see the reaction equations described below). Thus, unlike the oxomethod, the present process may not require high pressures, and may notuse harmful substances; consequently, it is possible to lower the costof safety management of plants and of plant construction, and to reducethe general production cost of high molecular alcohols. In addition, thepresent process may be a global environment-friendly, clean processbecause the side product of the present reaction may be only water,which is in contrast to the carbon dioxide produced as a side product inthe oxo method.

Overall reaction equations of major synthesis reactions of highmolecular alcohols are described below.2C₂H₅OH (ethanol)→C₄H₉OH (1-butanol )+H₂O (water)  (2)3C₂H₅OH (ethanol)→C₆H₁₃OH (hexanol)+2H₂O (water)  (3)4C₂H₅OH (ethanol)→C₈H₁₇OH (octanol)+3H₂O (water)  (4)5C₂H₅OH (ethanol)→C₁₀H₂₁OH (decanol)+4H₂O (water)  (5)

Based on the ratio of synthesis amounts of these high molecularalcohols, it may be considered that the synthesis reactions of highmolecular alcohols from ethanol, catalyzed by calcium phosphate-basedcatalysts, may be consecutive reactions of ethanol. It may be furtherconsidered that high molecular alcohols having an even number of carbonatoms such as butanol having 4 carbon atoms, hexanol having 6 carbonatoms, octanol having 8 carbon atoms and decanol having 10 carbon atoms,may be synthesized from ethanol having 2 carbon atoms. Provided thathigh molecular alcohols mentioned above may be synthesized as a resultof the consecutive reactions of ethanol, the above-mentioned reactions(3) to (5) may be described as the following equations (6) to (8).C₄H₉OH (1-butanol)+C₂H₅OH (ethanol)→C₆H₁₃OH (hexanol)+H₂O (water)  (6)C₆H₁₃OH (hexanol)+C₂H₅OH (ethanol)→C₈H₁₇OH (octanol)+H₂O (water)  (7)C₈H₁₇OH (octanol)+C₂H₅OH (ethanol)→C₁₀H₂₁OH (decanol)+H₂O (water)  (8)

The present inventors have pursued their keen studies for the effect ofcontact times in ethanol conversion reactions, and as a result, havefound that the above-mentioned high molecular alcohols can besynthesized in a highly selective manner by contacting ethanol with acalcium phosphate-based catalyst for a contact time of 0.4 seconds orlonger. With regard to the relationship between the contact times andthe selectivity of reactants in catalytic reactions, it is common thatas the contact time is prolonged, the selectivity of a single substanceis decreased because of condensation polymerization of raw materials andmultiple reactions. In the process of the present application, however,the selectivity of high molecular alcohols can be improved by prolongingthe contact time to 0.4 second or longer at an arbitrary temperature.

With regard to the relationship between the contact times and theabundance ratios of high molecular alcohols, consecutive reactions ofethanol proceeded as the contact time was prolonged, and alcohols withlarger molecular weight were synthesized. This is attributed to the factthat these high molecular alcohols are reaction intermediates in ethanolconversion reactions catalyzed by hydroxyapatite catalysts.

Accordingly, it is an object of the invention to not encompass withinthe invention any previously known product, process of making theproduct, or method of using the product such that Applicants reserve theright and hereby disclose a disclaimer of any previously known product,process, or method. It is further noted that the invention does notintend to encompass within the scope of the invention any product,process, or making of the product or method of using the product, whichdoes not meet the written description and enablement requirements of theUSPTO (35 U.S.C. 112, first paragraph) or the EPO (Article 83 of theEPC), such that Applicants reserve the right and hereby disclose adisclaimer of any previously described product, process of making theproduct, or method of using the product.

It is noted that in this disclosure and particularly in the claimsand/or paragraphs, terms such as “comprises”, “comprised”, “comprising”and the like can have the meaning attributed to it in U.S. Patent law;e.g., they can mean “includes”, “included”, “including”, and the like;and that terms such as “consisting essentially of” and “consistsessentially of” have the meaning ascribed to them in U.S. Patent law,e.g., they allow for elements not explicitly recited, but excludeelements that are found in the prior art or that affect a basic or novelcharacteristic of the invention.

These and other embodiments are disclosed or are obvious from andencompassed by, the following Detailed Description.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawing, in which:

FIG. 1 is a graph showing the relationship between the contact times andthe selectivity of high molecular alcohols in Table 1.

FIG. 2 is a graph in which the part between the contact times of 0.0 and1.0 second in FIG. 1 is enlarged.

FIG. 3 is a graph showing the analytical results obtained by GC-MS.

FIG. 4 is a graph showing the relationship between the reactiontemperatures and the selectivity of 1-butanol.

DETAILED DESCRIPTION

As calcium phosphate-based catalysts, the following are known examples:hydroxyapatite C₁₀(PO₄)₆(OH)₂, tricalcium phosphate Ca₃(PO₄)₂, calciummonohydrogen phosphate CaHPO₄.(0˜2)H₂O, calcium diphosphate Ca₂P₂O₇,octacalcium phosphate Ca₈H₂(PO₄)₆.5H₂O, tetracalcium phosphateCa₄(PO₄)₂O, amorphous calcium phosphate Ca₃(PO4)₂.nH₂O, etc. Thoughhydroxyapatite is generally indicated by the stoichiometric compositionmentioned above, it can form an apatite structure even though it doesnot meet the stoichiometric composition. Such hydroxyapatite withnon-stoichiometric composition can be indicated byC₁₀—Z(HPO₄)Z(PO₄)₆—Z(OH)₂—Z.nH₂O {0<Z≦1, n=0˜2.5}. Amorphous calciumphosphate-based catalysts refer to calcium phosphate-based catalystswhich show halos in their x-ray diffraction patterns.

The present invention is designed to efficiently produce the highmolecular alcohols mentioned above by using these calciumphosphate-based catalysts to optimize the reaction conditions, i.e., thecontact time and the reaction temperature.

In the present invention, a method for producing calcium phosphate-basedcompounds used as catalysts is not particularly limited, and thecatalysts can be synthesized by publicly known synthesis methods such asthe solid phase reaction (dry method), the precipitation reaction (wetmethod), the solid phase reaction (wet method), and the hydrothermalsynthesis method.

For example, hydroxyapatite is synthesized as follows:

-   -   (1) solutions of calcium salt and phosphate salt at prescribed        concentrations are added dropwise, while adjusting its pH, to an        aqueous solution being stirred;    -   (2) precipitated products are recovered, washed, dried, ground,        and calcinated if necessary, and used as a raw material of        catalysts.

The preferred calcium salt is Ca(OH)₂ or Ca(NO₃)₂, and the preferredphosphate salt is ammonium phosphate salt. The Ca/P molar ratio ofhydroxyapatite can be controlled by directing the mixing ratio of saltsas raw materials and the synthesis conditions. For instance, when theaqueous solution is adjusted to be basic with ammonia water, etc., at atime of synthesis, the Ca/P molar ratio will be higher, and when theaqueous solution is adjusted to be neutral or weakly acidic with diluteacid, the Ca/P molar ratio will be lower. In addition, hydroxyapatitewherein the Ca/P molar ratio is controlled can be obtained by mixingcalcium phosphate-based catalysts with known Ca/P molar ratios and thencalcinating them in a water atmosphere.

In case hydroxyapatite is used as a catalyst, the Ca/P molar ratio isadjusted to a range of 1.4 to 1.8, preferably, 1.5 to 1.7, and thecalcination temperature and the calcination atmosphere are selected inaccordance with the purposes. At that time, it is preferred that thespecific surface area of the catalyst is 2 m²/g or larger.

Catalytically, the control of the Ca/P molar ratio in calciumphosphate-based catalysts refers to control of the types and thedistribution densities of solid acid sites and solid base sites, whichare active sites on the catalyst surface. Here, the intensity and theamount of acid sites and base sites can be assessed by NH₃-TPD(Temperature Programmed Desorption) and CO₂-TPD, or pyridine adsorption,indicator method, etc. In addition, as for methods for controlling theacidity and the basicity of the catalyst surface, a method to support ametal thereon is generally known.

For example, supporting dehydrogenation reaction accelerating-metalstypically including Ni, Zn, Cu, Pd or Pt on hydroxyapatite induces thesame effect as an increase in the Ca/P molar ratio, i.e., there is anincrease in the solid basicity. Further, regarding hydroxyapatite,supporting dehydration reaction accelerating-metals typically includingAl induces the same effect as a decrease in the Ca/P molar ratio, i.e.,there is an increase in the solid acidic feature. Therefore, theacidity/basicity of the surface of hydroxyapatite catalysts can bechanged also by supporting such metals thereon instead of changing theCa/P molar ratios. In addition, a plurality of metals can be supportedtogether for the purpose of the synergistic effect or the improvement ofdurability. Metals to be supported together include, for example,transition metals such as Zn, Co, Cr, Mo, W, Fe, Ni, Cu, Mn, Ti, V, Ga,Zr, Nb, Cd, In, Sn, Sb, Pb, La, Ce, Eu and Y; or noble metals such asPt, Pd, Rh, Au, Ir, Ru and Ag; and alkali metals or alkali earth metalssuch as Ba, Na, K, Li, Sr, Ca, Mg, Cs and Rb. In some cases, oxides orsulfides of these metals can also be used. These substances are used ina range of 0.05 to 70 mol % on the basis of calcium in calciumphosphate-based catalysts.

In the present invention, when high molecular alcohols and mixturesthereof are synthesized from ethanol as a raw material, wherein acalcium phosphate-based catalyst is used, control of the acidity and thebasicity of the catalyst surface (for instance, the Ca/P molar ratio ofthe calcium phosphate-based catalyst), and reaction conditions (contacttime, reaction temperature, pressure, etc.) are appropriately selectedin order to increase the selectivity of desired high molecular alcohols.

The calcium phosphate-based catalysts adjusted as described above can beused in any form, for example, in a form of granules, powders, etc., andalso can be used after they are formed into an arbitrary form such asspheres, pellets, honeycombs, as needed, and dried and calcinated. Thecalcium phosphate-based catalysts can be supported on conventionalcarriers well known to a person skilled in the art such as alumina,silica, alumina-silica, zeolite, and clay mineral. Calcination isconducted at 200° C. to 1200° C., preferably at 400° C. to 700° C.

The reaction temperature of the present application, suitable forsynthesizing high molecular alcohols by contacting ethanol with acalcium phosphate-based catalyst, is usually selected preferably from arange of 150° C. to 450° C., more preferably 200° C. to 350° C. Thoughthere is a means of maintaining the high selectivity of high molecularalcohols even when the temperature is 150° C. or lower, yield is loweredand economic efficiency is worsened due to the low conversion rate ofethanol. Further, in case the temperature is 450° C. or higher, thoughthe conversion rate of ethanol is increased, the selectivity of highmolecular alcohols is lowered, unwanted reaction products are increasedand there emerge a new problem of disposal of these products. Also,economic efficiency is worsened.

The contact time of the present application is usually 0.4 seconds orlonger, preferably 0.6 seconds or longer. When the time is shorter than0.4 seconds, synthesis yield is lowered and economic efficiency isworsened, due to the low selectivity of high molecular alcohols and thelow conversion rate of ethanol. In case the reaction is conducted in alow temperature range, a batch reactor, which is equivalent toinfinitely large contact time, can be also used to increase theconversion rate of ethanol. In the reaction conducted in a hightemperature range, when the contact time is prolonged, other reactionsare increased and the selectivity of high molecular alcohols isdecreased.

The reaction to synthesize high molecular alcohols from ethanol is anexothermic reaction. Consequently, when the high yield of high molecularalcohols is set as a target, temperature rise inside a reaction tower,caused by heat of reaction, becomes prominent. As a result, there emergeproblems such as a decrease in the selectivity of high molecularalcohols caused by the emergence of other reactions including ethanoldecomposition reactions, deterioration of catalysts caused by catalysttemperature rise, and a decrease in the durability of reactors.Therefore, in case of reactions to synthesize high molecular alcoholsfrom ethanol, it is more suitable for industrialization to set highselectivity as a goal than to pursue high yield. However, provided thata system for removing heat of reaction is introduced into a reactiontower, such limitation is not applied.

It is possible to react ethanol efficiently by contacting ethanol with acatalyst directly in the gas phase or in the presence of an inertcarrier gas such as nitrogen or helium. At that time, a reactive gassuch as hydrogen or hydrocarbon may be added to the carrier gas in orderto maintain the catalytic activity.

With regard to reaction forms in a reaction tower, any method such as abatch method, a continuous method, a fixed bed, a moving bed, afluidized bed or a slurry bed can be used, and the reaction can beconducted at normal pressure or under pressure. In case of highmolecular alcohol synthesis reactions, carbons are precipitated on thecatalyst surface due to prolonged period of use, and this may result ina decrease in the ethanol conversion rate and changes in the nature ofreactions. In such case, a regeneration treatment, wherein a catalyst isheated in oxygen atmosphere, is periodically conducted. The activity ofthe catalyst can be restored by this treatment. Consequently, in case ofreaction conditions under which a lot of carbons are precipitated oncatalysts, a plant operated in accordance with the above-mentionedsystem, in which a catalyst regeneration apparatus is incorporated, iseffective.

High molecular alcohols thus obtained can be separated and purified withthe use of conventionally used separation and purification methods, forexample, rectification, microporous membrane separation, extraction, andadsorption.

The invention will now be further described by way of the followingnon-limiting examples which further illustrate the invention, and arenot intended, nor should they be interpreted to, limit the scope of theinvention.

A catalyst was synthesized as follows. With regard to the obtainedpowder, a powder X-ray diffractometer M18XHF22 manufactured byMacScience was used for the crystal structure, and SA3100 manufacturedby COLTER and an X-ray fluorescence spectrometer RIX1000 manufactured byRigaku Denki Kogyo Co., Ltd. were used for the measurement of thespecific surface area and the Ca/P molar ratio, respectively.

EXAMPLES Example 1 Preparation of Catalyst

A solution prepared by dissolving 225.2 g of calcium nitrate:Ca(NO₃)2.4H₂O in 5.0 liters of distilled water and a solution preparedby dissolving 78.87 g of ammonium phosphate: (NH₄)2HPO₄ in 3.0 liters ofdistilled water were added dropwise to aqueous ammonia of which pH hadbeen adjusted to 9 to 11 under a nitrogen atmosphere, and the resultantmixture was stirred for one day. Subsequently, the mixture wasfiltrated, washed with water, and dried to obtain a powder. Ion-exchangewater was added to the obtained powder, and the resultant mixture wascrushed for 48 hours with a ball mill. The slip thus obtained wasmatured and dried at 140° C. in an oven. The resultant powder wascalcinated in the air at 600° C. for 2 hours to obtain a powderycatalytic composition whose Ca/P molar ratio was 1.64.

Example 2 Evaluation of Catalytic Property

A fixed bed gas flow catalytic reactor was used as a reactor. Thepowdery catalyst was formed into tablets of 14 to 26 mesh. The tabletswere filled in a reaction tube in an amount in accordance with thecontact time, and a thermal dehydration treatment was conducted as apretreatment under carrier gas (1% Ar/He-based; flow 112 ml/min)atmosphere, at 500° C. for 30 minutes. After the pretreatment, thetablets were reacted at normal pressure under the conditions of ethanolconcentration of 16 vol %, carrier gas flow 112 ml/min (total flow 134ml/min).

In case of the high molecular alcohol synthesis experiment, the reactiontemperature was fixed at 300° C., and the contact time was in a range of0.02 to 29.4 seconds. In the optimization experiment of 1-butanolsynthesis conditions, the contact time was fixed at 1.0 second, theethanol concentration was 8.1%, and the reaction temperature was in arange of 150 to 500° C.

A gas chromatography mass spectrometer (GC-MS) was used for theidentification of the components of the reaction gas, and a gaschromatography (GC) (detector: FID) was used for the measurement of theethanol conversion rate and the selectivity of the synthetic gas. Atthat time, for the purpose of calculating the selectivity of ethanol asa raw material, butanol, hexanol, octanol and decanol, carbon molarresponse correction factors of 0.70, 0.85, 0.90, 0.93 and 0.94 wereused, respectively.Ethanol conversion rate (%)=(1-number of moles of carbon in1-ethanol/total number of moles of carbon)×100Selectivity of 1-butanol (%)=(number of moles of carbon in1-butanol/total number of moles of carbon)×100

The selectivities of hexanol, octanol and decanol are calculated in asame manner as in the case of 1-butanol.Selectivity of high molecular alcohols (%)=selectivity of1-butanol+selectivity of hexanol+selectivity of octanol+selectivity ofdecanol.

The results of the experiment are shown in Table 1, FIG. 1, and FIG. 2(an enlarged view of the part between the contact times of 0.0 and 1.0second in FIG. 1).

TABLE 1 Contact time (second) 0.02 0.08 0.13 0.22 0.31 0.42 0.63 0.891.34 1.78 2.40 3.56 7.27 14.60 29.40 Selectivity 2.2 7.9 12.8 22.0 35.758.5 70.3 77.1 79.1 77.9 75.8 72.1 64.5 55.6 45.4 of 1-butanol (%)Selectivity 0.3 1.5 3.3 3.5 4.5 4.9 6.0 6.4 7.3 8.6 10.7 13.4 20.2 23.825.2 of hexanol (%) Selectivity 0.0 0.1 0.2 0.2 0.3 0.3 0.4 0.5 0.8 1.11.8 2.4 4.0 6.9 9.5 of octanol (%) Selectivity 0.0 0.0 0.0 0.0 0.0 0.00.1 0.1 0.2 0.2 0.3 0.5 1.3 2.4 3.9 of decanol (%) Selectivity 2.4 9.516.3 25.7 40.5 63.7 76.8 84.0 87.3 87.8 88.6 88.5 90.0 88.7 84.0 ofpolymeric alcohols (%)

Table 1 shows the relationship between the contact times and theselectivity of high molecular alcohols when the ethanol conversionexperiment was conducted with the use of a hydroxyapatite catalyst at anethanol concentration of 16% and at a reaction temperature of 300° C.

The selectivity of 1-butanol reached its maximum value at the contacttime of 1.34 seconds, and decreased when the contact time was longerthan that. The selectivity of decanol, octanol and hexanol were low, inthis order. Up to the contact time of 29.4 seconds, each of selectivitywas increased as the contact time was prolonged.

Though the selectivity of high molecular alcohols was very low, 2.4% atthe contact time of 0.02 second, it rapidly increased as the contacttime was prolonged, and it exceeded 60% at the contact time of 0.4second. Further, when the contact time was 0.6 second or longer, theselectivity of high molecular alcohols was very high as 70% or more,which is a value advantageous for industrialization.

Example 3 Example of Analysis by Gas Chromatography Mass Spectrometer(GC-MS)

The ethanol conversion experiment was conducted with the use of ahydroxyapatite catalyst at an ethanol concentration of 16%, for acontact time of 1.78 seconds and at a reaction temperature of 300° C.,and an analysis was conducted with GC-MS. The results are shown in FIG.3.

The peaks of 1-butanol, hexanol (2 types: iso and normal), octanol (2types: iso and normal), and decanol (3 types: iso and normal) can beobserved at the retention times of 8.5 minutes, 13 to 14 minutes, 17 to18 minutes, and 20 to 22 minutes, respectively.

It can be seen from this result that high molecular alcohols having 4 ormore and an even number of carbon atoms are synthesized selectively.

Example 4 Evaluation of Reaction Temperature and the Selectivity of1-butanol

The ethanol conversion experiment was conducted with the use of ahydroxyapatite catalyst at an ethanol concentration of 8.1%, for acontact time of 1.0 second. In addition, a same ethanol conversionexperiment, except that the contact time was changed to 0.3 second, wasconducted for comparison. The results are shown in FIG. 4.

As a result that synthesis properties of 1-butanol at the contact times1.0 second and 0.3 second were compared, the selectivity of 1-butanol atthe contact time of 1.0 second was higher than that of 1-butanol at thecontact time of 0.3 second by about 12% at maximum. When the reactiontemperatures at the maximum values were compared, the temperature at thecontact time of 1.0 second was lower than the temperature at the contacttime of 0.3 second by about 75° C.

INDUSTRIAL APPLICABILITY

The catalyst according to the method of the present application can beproduced at a low cost and easily, and moreover, is stable to reactionsand regeneration treatments. With the catalyst, it is possible toefficiently obtain high molecular alcohols from ethanol by selectingreaction temperatures and contact times.

The high molecular alcohols produced via the present invention has clearindustrial applications. For example, butanol can be used as a solventfor a wide variety of chemical and textile processes, in organicsynthesis and as a chemical intermediate. It can also be used as a paintthinner and a solvent in other coating applications, as a component inhydraulic and brake fluids, as a base for perfumes, and potentially as abiofuel. Octanol can be used in the manufacture of various esters (bothsynthetic and naturally occurring), such as octyl acetate, which areused in perfumes and flavors. Finally, decanol can be used in themanufacture of plasticizers, lubricants, surfactants and solvents.

The invention is further described by the following numbered paragraphs:

i. A method for synthesizing a high molecular alcohol having 4 or moreand an even number of carbon atoms, wherein ethanol is brought intocontact with calcium phosphate for a contact time of 0.4 second orlonger.

ii. A method for synthesizing 1-butanol, wherein ethanol is brought intocontact with calcium phosphate for a contact time of 0.4 second orlonger, and at 200° C. to 350° C.

iii. The method for synthesizing a high molecular alcohol according toparagraph i, wherein the calcium phosphate is hydroxyapatite.

iv. The method for synthesizing 1-butanol according to paragraph ii,wherein the calcium phosphate is hydroxyapatite.

Having thus described in detail preferred embodiments of the presentinvention, it is to be understood that the invention defined by theabove paragraphs is not to be limited to particular details set forth inthe above description as many apparent variations thereof are possiblewithout departing from the spirit or scope of the present invention.

1. A method for synthesizing one or more high molecular alcohols having6 or more and an even number of carbon atoms, comprising contactingethanol with calcium phosphate for a contact time of 0.6 second orlonger.
 2. The method for synthesizing one or more high molecularalcohols according to claim 1, wherein the calcium phosphate ishydroxyapatite.
 3. The method of claim 1, wherein water is synthesizedby the method.
 4. The method of claim 2, wherein the ethanol iscontacted with the calcium phosphate at 200° C. to 350° C.
 5. The methodof claim 1, wherein the contact time is 0.63 to 29.40 seconds.
 6. Themethod of claim 5, wherein the one or more high molecular alcoholscomprise hexanol, and wherein the selectivity for hexanol is 6.0 to25.2%.
 7. The method of claim 5, wherein the one or more high molecularalcohols comprise octanol, and wherein the selectivity for octanol is0.4 to 9.5%.
 8. The method of claim 5, wherein the one or more highmolecular alcohols comprise decanol, and wherein the selectivity fordecanol is 0.1 to 3.9%.
 9. The method of claim 5, wherein the one ormore high molecular alcohols comprise hexanol, octanol, and decanol; andwherein the selectivity for hexanol, octanol, and decanol in combinationis 6.5 to 38.6%.
 10. The method of claim 5, wherein the one or more highmolecular alcohols comprise hexanol, octanol, and decanol; wherein theselectivity for hexanol is 6.0 to 25.2%, the selectivity for octanol is0.4 to 9.5%, and the selectivity for decanol is 0.1 to 3.9%.
 11. Themethod of claim 1, wherein the ethanol is synthesized by fermentation.12. A method for synthesizing 1-butanol, comprising contacting ethanolwith calcium phosphate for a contact time of 0.6 second or longer,wherein the selectivity for butanol is 70.3% or more.
 13. The method ofclaim 12, wherein the contact time is 0.63 to 3.56 second.
 14. Themethod of claim 13, wherein the selectivity for butanol is 70.3% to79.1%.
 15. The method of claim 12, wherein the calcium phosphate ishydroxyapatite.
 16. The method of claim 12, wherein the ethanol iscontacted with the calcium phosphate at 200° C. to 350° C.
 17. Themethod of claim 12, wherein the ethanol is synthesized by fermentation.18. The method of claim 12, wherein the selectivity for butanol is 70.3%to 79.1%.
 19. A method for synthesizing 1-butanol at a selectivity of70.3% or more, comprising contacting ethanol with calcium phosphate fora contact time of 0.6 second or longer, and at 200° C. or more to lessthan 350° C., wherein the calcium phosphate does not support a metal.